Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6619e381ca05cd2…

MALICIOUS

PDF

97.4 KB Created: 2021-08-09 14:08:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 4ebebbb7e62b9aea845b790b1322caea SHA-1: e70ffdbfae4a397843a3263b2011afefaa38ab11 SHA-256: b6619e381ca05cd26ec3d51376b2a1b583d2d1f6383ec1c4c95772164c13db1c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be metadata from the wkhtmltopdf tool rather than user-readable content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://irlanc.ru/uplcv?utm_term=classification+worksheet+answer+key+biology PDF link annotation
    • http://kag.fr/userfiles/file/pupegoronupilukajibariz.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/d1b86e5e9d8bf108bd8ed02882543e96/ripivipirotefadovarama.pdfIn PDF document text
    • https://aspaeng.com/files/image/files/23402701194.pdfIn PDF document text
    • https://actaviaserica.org/board/file/files/46465289106.pdfIn PDF document text
    • http://josephpowellfamilyreunion.com/clients/0/04/04c15d356d3082020e114f8c0300f46e/File/75516180288.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c7aa096fc7a---fezojefunepezu.pdfIn PDF document text
    • http://watch62.ru/files/files/palinadeditus.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a95335b691d---8799927232.pdfIn PDF document text
    • http://dichvuketoansg.com/luutru/files/vigozenujigiris.pdfIn PDF document text
    • https://huanghecables.com/d/files/37742306144.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/pokogo.pdfIn PDF document text
    • https://www.nvsrolko.org/ckfinder/userfiles/files/85504293722.pdfIn PDF document text
    • http://jarosi.hu/files/file/tuvuporesaji.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/2a795965094e1a0814c61b6b480c60ad/38833488584.pdfIn PDF document text
    • https://cevhertemizlik.com/userfiles/files/zudinobikusadef.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/11pj7h43k08lq10q80la81ebrf/vinirili.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/delj8pl1ld085sitmr55ics303/61921008571.pdfIn PDF document text
    • http://kbchina.de/upload/1216660122.pdfIn PDF document text
    • http://dienmaythanglong.org/uploads/files/gigigopojimewusazuf.pdfIn PDF document text
    • http://gulfcoolcontracting.com/uploads/userfiles/file/file/vomoxosozevupirog.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/97ud74lec91v5gh4rjr835g9kr/50942974214.pdfIn PDF document text
    • http://middlegeorgiacoinclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c4defe4a47---16743145298.pdfIn PDF document text
    • http://altinay-law.com/images/file/27382709611.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011613.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11613 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012e2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E2A 11080 bytes
SHA-256: aabe86bb0e4592357d58f02680c3f94bb2e95ffc4acbd100b66372672f2fe6d9
font_02_sfnt_off0001480a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1480A 18416 bytes
SHA-256: 596b48e148d7efe6bc07b5aad533f1d8b611f5453e27e895b4eff7bd4a22a417